What Is The Measurements Of a King Size Mattress? Standard Dimensions Explained
If you’re asking “What Is The Measurements Of a King Size Mattress?”, you’re likely trying to figure out if a king bed will fit comfortably in your bedroom and work for your sleep needs. This guide covers standard king size dimensions, how they compare to other mattress sizes, and what else to consider before choosing one.
What are the standard measurements of a king size mattress?
In most regions that use inches and feet, the standard king size mattress measures:
- 76 inches wide x 80 inches long
- Approximately 193 cm x 203 cm
This size is sometimes called an “Eastern King” and is the most common version of a king mattress.
A king mattress is essentially the same length as a standard queen, but wider. That extra width is what makes a king particularly appealing for couples or anyone who likes more personal space in bed.
Why do the measurements of a king size mattress matter?
Knowing what is the measurements of a king size mattress helps you:
- Check bedroom fit – Will there be enough space to walk around the bed and place furniture?
- Plan for bedding – Sheets, mattress protectors, and bed frames all need the right size.
- Consider doorway and stair access – King mattresses can be bulky to move.
- Compare to other sizes – You can decide if you truly need a king or if a queen or California king might make more sense.
A king mattress can make a room feel luxurious, but in a smaller bedroom it may feel cramped. Measuring ahead of time avoids surprises.
How does a king mattress compare to other common sizes?
Here’s a simple overview of how a standard king compares to other popular sizes:
| Mattress Size | Typical Measurements (W x L) | Notes |
|---|---|---|
| Full/Double | 54" x 75" (137 x 191 cm) | For one sleeper or smaller spaces |
| Queen | 60" x 80" (152 x 203 cm) | Common for couples |
| King | 76" x 80" (193 x 203 cm) | Extra width for couples |
| California King | 72" x 84" (183 x 213 cm) | Narrower but longer than a standard king |
➡️ Key difference: A king is wider than a queen and California king, but a California king is longer.
Are there different types of king size measurements?
Yes. When people ask “What Is The Measurements Of a King Size Mattress?”, they often discover there are several versions:
Standard King (Eastern King)
- 76" x 80" (193 x 203 cm)
- Widest common mattress size for residential use.
California King
- 72" x 84" (183 x 213 cm)
- Slightly narrower and longer than a standard king.
Split King
- Typically two twin XL mattresses side by side:
- Each: 38" x 80" (97 x 203 cm)
- Combined: 76" x 80" (193 x 203 cm)
- Combined measurements match a standard king, but in two separate pieces.
Exact measurements can vary slightly (often by about an inch) depending on the manufacturer, but these listed dimensions are widely recognized as standard.
How much space do you need for a king size mattress?
Beyond “What Is The Measurements Of a King Size Mattress?”, it’s also useful to know how much room around it you need.
A common guideline is to leave at least:
- 24–30 inches (about 60–75 cm) of open space on each side of the bed
- At least 24 inches at the foot of the bed if possible
This allows for:
- Easier movement around the room
- Space for nightstands
- A more open, comfortable layout
If your room is very tight once a king is placed, you may want to consider a queen or rearrange other furniture.
Do bedding and bed frames match these exact measurements?
Most bedding and bed frames are designed to fit the standard measurements of a king size mattress, but there are a few things to keep in mind:
- Sheets and protectors are usually labeled “King” and made for 76" x 80". Deep-pocket versions are for thicker mattresses, not different lengths or widths.
- Bed frames may be slightly larger than the mattress to account for structure and design.
- Headboards and footboards can add to the total footprint of the bed, even though the mattress size stays the same.
It’s a good idea to confirm both the mattress dimensions and the outer dimensions of the frame if you’re working with a limited space.
Common misconceptions about king size measurements
“A king is the biggest size available.”
A king is the widest standard size, but some specialty or oversized mattresses (beyond everyday retail options) can be larger. These are less common and not standardized.
“California king is bigger in every way.”
A California king is longer but not wider than a standard king. Taller sleepers may prefer the extra length, while couples often choose standard king for the added width.
“All king mattresses are exactly the same size.”
Most follow the standard dimensions, but minor variations of about an inch can happen. This usually does not affect standard king bedding, but it’s worth checking if you need a very precise fit.
✔️ Quick Mattress Takeaways
Key points about “What Is The Measurements Of a King Size Mattress”:
- Standard king size: about 76" x 80" (193 x 203 cm)
- It’s wider than a queen and shorter and wider than a California king.
- A split king is two twin XL mattresses that equal the same overall measurements.
- Leave adequate space around the bed so the room remains functional and comfortable.
- Check both mattress size and frame size when planning your layout.
- Slight variations in size can occur between manufacturers, but the above measurements are widely accepted as standard.
Understanding what is the measurements of a king size mattress gives you a solid foundation for planning your bedroom setup, choosing compatible bedding, and deciding whether a king is the right fit for your space and sleeping preferences.
